The top US intelligence chief wants a criminal probe into bombshell leaks of US monitoring of internet users and phone records.

Director of National Intelligence James Clapper confirmed on Saturday that US spy agencies use a system called PRISM to gather data trails left by targeted foreign citizens using the internet outside the United States.

But in an interview with NBC News, on Sunday, he called the disclosures literally gutwrenching and said they had caused huge, grave damage to US intelligence capabilities.

The NSA has filed a crimes report on this already, Clapper told NBC, referring to the leaks to the Guardian and The Washington Post.

A 29yearold government contractor, Edward Snowden has been revealed as the sourc shoes sale online uk e of the leaks.

Snowden said he was motivated by a desire to inform the public about the massive surveillance machine.

I have no intention of hiding who I am because I know I have done nothing wrong, he said.

Clapper said he was profoundly offended that a disgruntled intelligence officer was a source for the leak to The Wa shoes sale online uk shington Post. This is someone who for whatever reason has chosen to violate a sacred trust for this country, he said.

And, so, I hope were able to track down whoevers doing this, because it is extremely damaging to, and it affects the safety and security of this country.

One top US lawmaker, Pete King, chairman of the House Subcommittee on Counterterrorism and Intelligence, in a statement on Sunday called for Snowdens extradition to the US, saying he must be prosecuted to the fullest extent of the law. Yahoo! issued a similar denial.

Under PRISM, which has been running for six years, the US National Security Agency can issue directives to internet firms demanding access to emails, online chats, pictures, files, videos and more uploaded by foreign users.

But Clappers statement described a syste shoes sale online uk m whereby the government must apply to a secret US court for permission to target individuals or entities then issue a request to the service provider. shoes sale online uk